(1) how do the kidneys clean the blood? . a) by breaking down nutrients. b) kidneys clean the blood by filtering it to remove wastes. c) by absorbing nutrients. d) by destroying microbes and preventing preventing infection. (2) what role does skin play in the excretory system? . a) secretes excess water as sweat. b) protects against pathogens. c) absorbs water through osmosis. d) facilitates gas exchange

Sarah and john are having a discussion on genetic diversity. sarah believes that it happen over a long period of time. john it happens immediately. who is correct? a. sarah is correct because genetic diversity occurs over a long period of time. b. john is correct because genetic diversity occurs immediately. c. both are correct because genetic variation can occur or long period of time. d. neither are correct because genetic diversity occurs over any period of time